In the midst of a multi-year drought, we have received many inquiries about preparing and protecting trees for summer drought stress. Shrubs, perennials, and groundcovers are relatively inexpensive to replace. However, replacing old trees that have died is a long process that carries high costs. Depending on age of the tree that is lost; it may take new trees 25 years or longer to grow to size. You have to factor in the cost of tree removal and stump grinding in addition to the cost of the new plant material.

There are many ways to protect valuable shade and specimen trees during a drought.

1. If the tree is growing in turf, remove the existing lawn and install a thick layer of mulch to reduce water loss. Turfgrass competes with the tree for moisture. Grass is able to use the irrigation water before it reaches the tree roots. Turf requires regular nitrogen fertilization to encourage lush growth. Trees grown in lawns push out excessive foliage growth. The extra foliage increases the rate of transpiration and water use. Removing the lawn will positively affect the tree.
2. Mulch beyond the drip line of the tree. Tree canopies divert rainwater to the feeder roots at the drip line of the tree. Roots in this area are responsible for the majority of the water uptake of the tree.
3. Deep water your trees to a depth of 1 foot. With drip irrigation, this is an easy task to achieve. If using overhead spray irrigation; eliminate runoff and utilize multiple cycles to ensure irrigation water percolates deep into the soil profile.
4. Soil injections provide moisture directly to the root-zone of the tree. This method of deep watering is especially helpful on drought stressed or declining trees.
5. Prune the canopy of the tree to reduce excess foliage, weak branches, and diseased plant material. Dead and dying limbs should be removed. These limbs may harbor insect borers or canker disease fungi that can contribute to further dieback and decline. If tree crowns are very dense, light thinning will help reduce demands for water and nutrients. But avoid significant over pruning of live branches, as it will add additional stress from defoliation and wounding.

A healthy tree is more resistant to drought stress. Proactively monitoring the tree for symptoms of stress from pests and diseases is the best method of Integrated Pest Management (IPM). Pests and diseases can wreak-havoc on drought-stressed trees.

Mature trees are one of the most valuable elements of any landscape. Improper care or neglect can permanently ruin the long-term health of a tree. The best advice is to contact a certified arborist and schedule a consultation. To schedule an appointment with our Tree Sculpture arborist, call us today at 510-562-4000.

Fire season is just around the corner. In fact, Wildfire awareness week is May 3rd through the 9th. As the hillsides turn golden, we turn our attention to weed abatement and annual mowing for fire clearance. We encourage everyone to be prepared. Therefore, we want to remind everyone to maintain a defensible space around your property. Be sure to check with your fire district for specific codes as rules and regulations vary.

Here are 4 basic steps you can take within Zone 1 or the immediate vicinity (30-50 feet) of your home:

1. Remove all dead and dying plants, dry plant debris, and pine needles.
2. Prune any tree branches that are within 10’ of your chimney or that overhang onto your house.
3. Maintain separation from neighboring trees to prevent fire from spreading from one tree to another.
4. Keep plants properly irrigated in this zone: a properly irrigated landscape helps to resist fire. A layer of mulch helps keep plants properly hydrated. To learn more about the benefits of mulch, visit the following link to our previous post: Three Benefits of Mulch

Here are additional steps you can take within Zone 2 or the surrounding 50-70 feet:

All plantings should be sparse to prevent fire from spreading from plant to plant (horizontal spacing).

Due to the on-going drought, we have experienced multiple years of below average rainfall. Many older established trees, which receive little to no supplemental irrigation, have begun to show symptoms of drought stress. You may notice wilting leaves, brown or golden foliage, severe needle or foliage drop, all of which are signs of drought stress. Even irrigated landscape shrubs may begin to show stress with heavy watering restrictions in place.

The best way to protect these species is by incorporating a mulch layer to the root zone. Mulch benefits the landscape in multiple ways, including these three:

1. A layer of mulch helps to insulate the soil. This insulation keeps the root zone temperatures more moderate and reduces plant stress.
2. Mulch limits water-loss due to evaporation. This ensures that more water will be available to the trees and shrubs.
3. Mulch reduces weed growth. Weeds compete with landscape species for valuable water.

In an effort to promote the benefits of mulch, we’re offering a 5% discount on all mulch proposals of 35 yards or more signed between May 1st and July 31st 2015. Please reference this post to apply your discount. Offer excludes arbor chips.

Please note that in some instances mulch alone may not be sufficient for establishing soil conditions needed to maintain plant health. Contact us today to learn whether aeration, deep root watering and fertilization could help to preserve your most valued landscape assets.

How do you prepare your lawn for the stress of summer? In the past, the answer was to increase the irrigation water to your lawn. Now that we are mired in drought and irrigation restrictions are in effect, we cannot maintain lush, green lawns throughout the summer if we hope to meet strict water budgets. In poor soils, lawns will perish with the summer heat and reduced water.

To prepare your lawn for summer, we recommend topdressing with a soil specific compost mixture. Topdressing is a process that helps to gradually change soil composition by amending soils to improve their properties.

In Alameda and San Francisco, soils have little ability to retain moisture due to their sandy composition. Water quickly drains through sandy soils, so they must be irrigated more often. With watering limited to two days per week, it can be difficult to keep a lawn lush on sandy soils, even during the cooler months. By the end of summer, lawns will show severe stress. In order to improve moisture retention, these sandy soils must be topdressed to begin to change their composition.

In Walnut Creek and Moraga, soils are comprised of heavy clay with relatively little loam or sand. Clay soils are vastly different from sandy soils. Clay soils are capable of retaining moisture for a longer period of time than sandy soils, but have very little oxygen space and drain poorly. Because of their ability to retain moisture, these soils do not have to be irrigated as often, but care must be taken not to oversaturate the soils. Topdressing clay soil can greatly improve drainage over time while still allowing the soils to retain moisture.

How to Topdress Your Lawn

The best time to topdress a lawn is during the cooler months of the year. To start the topdressing process, you must first mow your lawn to a lower height. The lawn is then aerated to remove small cores of soil throughout. These voids provide a transitional space for the topdressing material, which will be added in the next step. This transitional space helps to prevent soil layering issues.

Topdressing materials are chosen based on the desired outcome. In sandy soils, the best topdressing material is a loamy-compost mixture (a small amount of clay/finer particles can be incorporated). Clay soils are capable of holding a large amount of moisture, but when saturated have very little oxygen space. We recommend topdressing clay soils with a loamy-compost mixture that consists of large particles. Gypsum is another common amendment for clay soils. This will improve the soil’s ability to drain and increases the fertility.

Topdressing can greatly improve the soil texture, but it is a slow process. It is best to topdress in thin layers. Problems can arise when vastly different soils are layered in thick sheets. Water will always infiltrate and drain from one layer quicker than the other layer, causing standing water and anaerobic conditions where the two layers meet.

At Tree Sculpture and Terra Landscape, we have thorough knowledge of the properties of Bay Area soils. We believe improving the quality of your landscape starts from the ground up. To further discuss the options for improving your landscape, give us a call today.

When it comes to pruning, correct timing minimizes stress and allows a plant to heal under optimal conditions. Diseased, weak and / or dangerous branches should always be pruned as soon as possible. When it comes to Pine trees, now is the ideal time for aesthetic or structural pruning.

Pine trees are dormant during the late winter. Pine bark beetle, a major pest in California, is also dormant during this period. Pruning cuts made in the late winter will callus quickly in the early spring before the beetle is active. Once the callus is completely formed, the wound is no longer susceptible to attack.

Bark beetles feed on the vascular tissue of Pine trees. As the beetles feed, they can spread a fungal disease called pitch canker. Pitch canker causes dieback of branches and an overall decline in health. Open pruning wounds are a direct invitation to these beetles; who chew out tunnels and lay their eggs inside the tree. These eggs hatch as larvae and begin feeding and mining tunnels and ultimately they emerge as adults. Adult Pine bark beetles are typically first seen in late spring, then can be seen from late summer to early fall.

Pruning pines during the spring or summer time is not recommended. Warming temperatures, high humidity levels, and open wounds are a recipe for fungal diseases or bark beetle attack. Bark beetles are highly active during this time, so avoid pruning during this time to limit the spread of pitch canker. Pruning cuts made in the fall may not callus until the spring. An open wound in the fall is susceptible to attack from adult pine bark beetles looking to lay eggs before the cold arrives. For these reasons, pruning a Pine tree in the fall is typically not recommended.

At Tree Sculpture, we have a thorough understanding of the many factors that can impact the health of your trees and landscape. To learn more about the best time to prune your trees, give us a call today.